usb_charger: Move part-specific code to usb_switch driver

Previously usb_charger.c supported only pi3usb9281, but now support for
additional parts is required. Move pericom-specific code (including the
usb_charger tasks that handles various quirks of that part) to the
pi3usb9281 usb_switch driver.

Going forward, usb_switch drivers must implement
usb_charger_set_switches() and must have some method (such as a task or
interrupt handler) to update charge_manager with information about
attached chargers.

BUG=chrome-os-partner:53363
BRANCH=None
TEST=`make buildall -j`

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I4df74e043d8cf2e532d48c39c73b7dc2930f7d3b
Reviewed-on: https://chromium-review.googlesource.com/344289
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

4 files changed, 204 insertions, 228 deletions

diff --git a/common/usb_charger.c b/common/usb_charger.c
index c56e0f4d0f..8e938233a3 100644
--- a/common/usb_charger.c
+++ b/common/usb_charger.c
@@ -4,40 +4,23 @@
  */
 
 /*
- * USB charger / BC1.2 task. This code assumes that CONFIG_CHARGE_MANAGER
- * is defined and implemented. PI3USB9281 is the only charger detector
- * currently supported.
+ * USB charger interface routines. This code assumes that CONFIG_CHARGE_MANAGER
+ * is defined and implemented.
+ * usb_charger_set_switches() must be implemented by a companion
+ * usb_switch driver.
+ * In addition,  USB switch-specific usb_charger task or interrupt routine
+ * is necessary to update charge_manager with detected charger attributes.
  */
 
 #include "charge_manager.h"
 #include "common.h"
 #include "console.h"
-#include "ec_commands.h"
 #include "gpio.h"
 #include "hooks.h"
-#include "pi3usb9281.h"
 #include "task.h"
-#include "timer.h"
 #include "usb_charge.h"
 #include "usb_pd.h"
 
-#define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
-
-/* Wait after a charger is detected to debounce pin contact order */
-#define USB_CHG_DEBOUNCE_DELAY_MS 1000
-/*
- * Wait after reset, before re-enabling attach interrupt, so that the
- * spurious attach interrupt from certain ports is ignored.
- */
-#define USB_CHG_RESET_DELAY_MS 100
-
-/*
- * Store the state of our USB data switches so that they can be restored
- * after pericom reset.
- */
-static int usb_switch_state[CONFIG_USB_PD_PORT_COUNT];
-static struct mutex usb_switch_lock[CONFIG_USB_PD_PORT_COUNT];
-
 static void update_vbus_supplier(int port, int vbus_level)
 {
 	struct charge_port_info charge;
@@ -67,19 +50,6 @@ int usb_charger_port_is_sourcing_vbus(int port)
 	return 0;
 }
 
-void usb_charger_set_switches(int port, enum usb_switch setting)
-{
-	/* If switch is not changing then return */
-	if (setting == usb_switch_state[port])
-		return;
-
-	mutex_lock(&usb_switch_lock[port]);
-	if (setting != USB_SWITCH_RESTORE)
-		usb_switch_state[port] = setting;
-	pi3usb9281_set_switches(port, usb_switch_state[port]);
-	mutex_unlock(&usb_switch_lock[port]);
-}
-
 void usb_charger_vbus_change(int port, int vbus_level)
 {
 	/* If VBUS has transitioned low, notify PD module directly */
@@ -94,159 +64,6 @@ void usb_charger_vbus_change(int port, int vbus_level)
 #endif
 }
 
-static void usb_charger_bc12_detect(int port)
-{
-	int device_type, charger_status;
-	struct charge_port_info charge;
-	int type;
-
-	charge.voltage = USB_CHARGER_VOLTAGE_MV;
-
-	if (usb_charger_port_is_sourcing_vbus(port)) {
-		/* If we're sourcing VBUS then we're not charging */
-		device_type = charger_status = 0;
-	} else {
-		/* Set device type */
-		device_type = pi3usb9281_get_device_type(port);
-		charger_status = pi3usb9281_get_charger_status(port);
-	}
-
-	/* Debounce pin plug order if we detect a charger */
-	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
-		/* next operation might trigger a detach interrupt */
-		pi3usb9281_disable_interrupts(port);
-		/*
-		 * Ensure D+/D- are open before resetting
-		 * Note: we can't simply call pi3usb9281_set_switches() because
-		 * another task might override it and set the switches closed.
-		 */
-		pi3usb9281_set_switch_manual(port, 1);
-		pi3usb9281_set_pins(port, 0);
-
-		/* Delay to debounce pin attach order */
-		msleep(USB_CHG_DEBOUNCE_DELAY_MS);
-
-		/*
-		 * Trigger chip reset to refresh detection registers.
-		 * WARNING: This reset is acceptable for samus_pd,
-		 * but may not be acceptable for devices that have
-		 * an OTG / device mode, as we may be interrupting
-		 * the connection.
-		 */
-		pi3usb9281_reset(port);
-		/*
-		 * Restore data switch settings - switches return to
-		 * closed on reset until restored.
-		 */
-		usb_charger_set_switches(port, USB_SWITCH_RESTORE);
-		/* Clear possible disconnect interrupt */
-		pi3usb9281_get_interrupts(port);
-		/* Mask attach interrupt */
-		pi3usb9281_set_interrupt_mask(port,
-					      0xff &
-					      ~PI3USB9281_INT_ATTACH);
-		/* Re-enable interrupts */
-		pi3usb9281_enable_interrupts(port);
-		msleep(USB_CHG_RESET_DELAY_MS);
-
-		/* Clear possible attach interrupt */
-		pi3usb9281_get_interrupts(port);
-		/* Re-enable attach interrupt */
-		pi3usb9281_set_interrupt_mask(port, 0xff);
-
-		/* Re-read ID registers */
-		device_type = pi3usb9281_get_device_type(port);
-		charger_status = pi3usb9281_get_charger_status(port);
-	}
-
-	/* Attachment: decode + update available charge */
-	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
-		if (PI3USB9281_CHG_STATUS_ANY(charger_status))
-			type = CHARGE_SUPPLIER_PROPRIETARY;
-		else if (device_type & PI3USB9281_TYPE_CDP)
-			type = CHARGE_SUPPLIER_BC12_CDP;
-		else if (device_type & PI3USB9281_TYPE_DCP)
-			type = CHARGE_SUPPLIER_BC12_DCP;
-		else if (device_type & PI3USB9281_TYPE_SDP)
-			type = CHARGE_SUPPLIER_BC12_SDP;
-		else
-			type = CHARGE_SUPPLIER_OTHER;
-
-		charge.current = pi3usb9281_get_ilim(device_type,
-						     charger_status);
-		charge_manager_update_charge(type, port, &charge);
-	} else { /* Detachment: update available charge to 0 */
-		charge.current = 0;
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_PROPRIETARY,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_CDP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_DCP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_SDP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_OTHER,
-					port,
-					&charge);
-	}
-
-	/* notify host of power info change */
-	pd_send_host_event(PD_EVENT_POWER_CHANGE);
-}
-
-void usb_charger_task(void)
-{
-	const int attach_mask = PI3USB9281_INT_ATTACH | PI3USB9281_INT_DETACH;
-	int port = (task_get_current() == TASK_ID_USB_CHG_P0 ? 0 : 1);
-	int interrupt;
-	uint32_t evt;
-
-	/* Initialize chip and enable interrupts */
-	pi3usb9281_init(port);
-
-	usb_charger_bc12_detect(port);
-
-	while (1) {
-		/* Wait for interrupt */
-		evt = task_wait_event(-1);
-
-		/* Interrupt from the Pericom chip, determine charger type */
-		if (evt & USB_CHG_EVENT_BC12) {
-			/* Read interrupt register to clear on chip */
-			pi3usb9281_get_interrupts(port);
-			usb_charger_bc12_detect(port);
-		} else if (evt & USB_CHG_EVENT_INTR) {
-			/* Check the interrupt register, and clear on chip */
-			interrupt = pi3usb9281_get_interrupts(port);
-			if (interrupt & attach_mask)
-				usb_charger_bc12_detect(port);
-		}
-
-		/*
-		 * Re-enable interrupts on pericom charger detector since the
-		 * chip may periodically reset itself, and come back up with
-		 * registers in default state. TODO(crosbug.com/p/33823): Fix
-		 * these unwanted resets.
-		 */
-		if (evt & USB_CHG_EVENT_VBUS) {
-			pi3usb9281_enable_interrupts(port);
-#ifndef CONFIG_USB_PD_TCPM_VBUS
-			CPRINTS("VBUS p%d %d", port,
-				pd_snk_is_vbus_provided(port));
-#endif
-		}
-	}
-}
-
 static void usb_charger_init(void)
 {
 	int i;
diff --git a/driver/pi3usb9281.h b/driver/pi3usb9281.h
index 929476c81b..fc642435c6 100644
--- a/driver/pi3usb9281.h
+++ b/driver/pi3usb9281.h
@@ -71,6 +71,7 @@ struct pi3usb9281_config {
 /* Configuration struct defined at board level */
 extern struct pi3usb9281_config pi3usb9281_chips[];
 
+/* TODO: Make many of these functions static after Oak board changes. */
 /* Initialize chip and enable interrupts */
 void pi3usb9281_init(int port);
 
@@ -80,9 +81,6 @@ int pi3usb9281_enable_interrupts(int port);
 /* Disable all interrupts. */
 int pi3usb9281_disable_interrupts(int port);
 
-/* Set interrupt mask. */
-int pi3usb9281_set_interrupt_mask(int port, uint8_t mask);
-
 /* Get and clear current interrupt status. */
 int pi3usb9281_get_interrupts(int port);
 
@@ -92,19 +90,4 @@ int pi3usb9281_get_device_type(int port);
 /* Get attached charger status. */
 int pi3usb9281_get_charger_status(int port);
 
-/* Get charger current limit based on device type and charger status. */
-int pi3usb9281_get_ilim(int device_type, int charger_status);
-
-/* Set switch configuration to manual. */
-int pi3usb9281_set_switch_manual(int port, int val);
-
-/* Set bits to enable pins in manual switch register. */
-int pi3usb9281_set_pins(int port, uint8_t mask);
-
-/* Set D+/D-/Vbus switches to open or closed/auto-control. */
-int pi3usb9281_set_switches(int port, int open);
-
-/* Reset PI3USB9281. */
-int pi3usb9281_reset(int port);
-
 #endif /* __CROS_EC_PI3USB9281_H */
diff --git a/driver/usb_switch_pi3usb9281.c b/driver/usb_switch_pi3usb9281.c
index 063d7d3983..569438b761 100644
--- a/driver/usb_switch_pi3usb9281.c
+++ b/driver/usb_switch_pi3usb9281.c
@@ -5,13 +5,18 @@
  * Pericom PI3USB3281 USB port switch driver.
  */
 
+#include "charge_manager.h"
+#include "common.h"
 #include "console.h"
+#include "ec_commands.h"
 #include "gpio.h"
 #include "hooks.h"
 #include "i2c.h"
+#include "pi3usb9281.h"
 #include "task.h"
 #include "timer.h"
-#include "pi3usb9281.h"
+#include "usb_charge.h"
+#include "usb_pd.h"
 #include "util.h"
 
  /* Console output macros */
@@ -24,6 +29,18 @@
 /* Delay values */
 #define PI3USB9281_SW_RESET_DELAY 20
 
+/* Wait after a charger is detected to debounce pin contact order */
+#define PI3USB9281_DETECT_DEBOUNCE_DELAY_MS 1000
+/*
+ * Wait after reset, before re-enabling attach interrupt, so that the
+ * spurious attach interrupt from certain ports is ignored.
+ */
+#define PI3USB9281_RESET_DEBOUNCE_DELAY_MS 100
+
+/* Store the state of our USB data switches so that they can be restored. */
+static int usb_switch_state[CONFIG_USB_PD_PORT_COUNT];
+static struct mutex usb_switch_lock[CONFIG_USB_PD_PORT_COUNT];
+
 static void select_chip(int port)
 {
 	struct pi3usb9281_config *chip = &pi3usb9281_chips[port];
@@ -81,6 +98,11 @@ static int pi3usb9281_write_ctrl(int port, uint8_t ctrl)
 				PI3USB9281_CTRL_RSVD_1);
 }
 
+static int pi3usb9281_set_interrupt_mask(int port, uint8_t mask)
+{
+	return pi3usb9281_write(port, PI3USB9281_REG_INT_MASK, ~mask);
+}
+
 void pi3usb9281_init(int port)
 {
 	uint8_t dev_id;
@@ -118,11 +140,6 @@ int pi3usb9281_disable_interrupts(int port)
 	return rv;
 }
 
-int pi3usb9281_set_interrupt_mask(int port, uint8_t mask)
-{
-	return pi3usb9281_write(port, PI3USB9281_REG_INT_MASK, ~mask);
-}
-
 int pi3usb9281_get_interrupts(int port)
 {
 	return pi3usb9281_read(port, PI3USB9281_REG_INT);
@@ -138,7 +155,7 @@ int pi3usb9281_get_charger_status(int port)
 	return pi3usb9281_read(port, PI3USB9281_REG_CHG_STATUS) & 0x1f;
 }
 
-int pi3usb9281_get_ilim(int device_type, int charger_status)
+static int pi3usb9281_get_ilim(int device_type, int charger_status)
 {
 	/* Limit USB port current. 500mA for not listed types. */
 	int current_limit_ma = 500;
@@ -160,16 +177,7 @@ int pi3usb9281_get_ilim(int device_type, int charger_status)
 	return current_limit_ma;
 }
 
-int pi3usb9281_get_vbus(int port)
-{
-	int vbus = pi3usb9281_read(port, PI3USB9281_REG_VBUS);
-	if (vbus == 0xee)
-		return EC_ERROR_UNKNOWN;
-
-	return !!(vbus & 0x2);
-}
-
-int pi3usb9281_reset(int port)
+static int pi3usb9281_reset(int port)
 {
 	int rv = pi3usb9281_write(port, PI3USB9281_REG_RESET, 0x1);
 
@@ -180,7 +188,7 @@ int pi3usb9281_reset(int port)
 	return rv;
 }
 
-int pi3usb9281_set_switch_manual(int port, int val)
+static int pi3usb9281_set_switch_manual(int port, int val)
 {
 	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 
@@ -195,12 +203,12 @@ int pi3usb9281_set_switch_manual(int port, int val)
 	return pi3usb9281_write_ctrl(port, ctrl);
 }
 
-int pi3usb9281_set_pins(int port, uint8_t val)
+static int pi3usb9281_set_pins(int port, uint8_t val)
 {
 	return pi3usb9281_write(port, PI3USB9281_REG_MANUAL, val);
 }
 
-int pi3usb9281_set_switches(int port, int open)
+static int pi3usb9281_set_switches(int port, int open)
 {
 	uint8_t ctrl = pi3usb9281_read(port, PI3USB9281_REG_CONTROL);
 
@@ -214,3 +222,171 @@ int pi3usb9281_set_switches(int port, int open)
 
 	return pi3usb9281_write_ctrl(port, ctrl);
 }
+
+void usb_charger_set_switches(int port, enum usb_switch setting)
+{
+	/* If switch is not changing then return */
+	if (setting == usb_switch_state[port])
+		return;
+
+	mutex_lock(&usb_switch_lock[port]);
+	if (setting != USB_SWITCH_RESTORE)
+		usb_switch_state[port] = setting;
+
+	pi3usb9281_set_switches(port, usb_switch_state[port]);
+
+	mutex_unlock(&usb_switch_lock[port]);
+}
+
+static void bc12_detect(int port)
+{
+	int device_type, charger_status;
+	struct charge_port_info charge;
+	int type;
+
+	charge.voltage = USB_CHARGER_VOLTAGE_MV;
+
+	if (usb_charger_port_is_sourcing_vbus(port)) {
+		/* If we're sourcing VBUS then we're not charging */
+		device_type = charger_status = 0;
+	} else {
+		/* Set device type */
+		device_type = pi3usb9281_get_device_type(port);
+		charger_status = pi3usb9281_get_charger_status(port);
+	}
+
+	/* Debounce pin plug order if we detect a charger */
+	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
+		/* next operation might trigger a detach interrupt */
+		pi3usb9281_disable_interrupts(port);
+		/*
+		 * Ensure D+/D- are open before resetting
+		 * Note: we can't simply call pi3usb9281_set_switches() because
+		 * another task might override it and set the switches closed.
+		 */
+		pi3usb9281_set_switch_manual(port, 1);
+		pi3usb9281_set_pins(port, 0);
+
+		/* Delay to debounce pin attach order */
+		msleep(PI3USB9281_DETECT_DEBOUNCE_DELAY_MS);
+
+		/*
+		 * Trigger chip reset to refresh detection registers.
+		 * WARNING: This reset is acceptable for samus_pd,
+		 * but may not be acceptable for devices that have
+		 * an OTG / device mode, as we may be interrupting
+		 * the connection.
+		 */
+		pi3usb9281_reset(port);
+		/*
+		 * Restore data switch settings - switches return to
+		 * closed on reset until restored.
+		 */
+		usb_charger_set_switches(port, USB_SWITCH_RESTORE);
+		/* Clear possible disconnect interrupt */
+		pi3usb9281_get_interrupts(port);
+		/* Mask attach interrupt */
+		pi3usb9281_set_interrupt_mask(port,
+					      0xff &
+					      ~PI3USB9281_INT_ATTACH);
+		/* Re-enable interrupts */
+		pi3usb9281_enable_interrupts(port);
+		msleep(PI3USB9281_RESET_DEBOUNCE_DELAY_MS);
+
+		/* Clear possible attach interrupt */
+		pi3usb9281_get_interrupts(port);
+		/* Re-enable attach interrupt */
+		pi3usb9281_set_interrupt_mask(port, 0xff);
+
+		/* Re-read ID registers */
+		device_type = pi3usb9281_get_device_type(port);
+		charger_status = pi3usb9281_get_charger_status(port);
+	}
+
+	/* Attachment: decode + update available charge */
+	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
+		if (PI3USB9281_CHG_STATUS_ANY(charger_status))
+			type = CHARGE_SUPPLIER_PROPRIETARY;
+		else if (device_type & PI3USB9281_TYPE_CDP)
+			type = CHARGE_SUPPLIER_BC12_CDP;
+		else if (device_type & PI3USB9281_TYPE_DCP)
+			type = CHARGE_SUPPLIER_BC12_DCP;
+		else if (device_type & PI3USB9281_TYPE_SDP)
+			type = CHARGE_SUPPLIER_BC12_SDP;
+		else
+			type = CHARGE_SUPPLIER_OTHER;
+
+		charge.current = pi3usb9281_get_ilim(device_type,
+						     charger_status);
+		charge_manager_update_charge(type, port, &charge);
+	} else { /* Detachment: update available charge to 0 */
+		charge.current = 0;
+		charge_manager_update_charge(
+					CHARGE_SUPPLIER_PROPRIETARY,
+					port,
+					&charge);
+		charge_manager_update_charge(
+					CHARGE_SUPPLIER_BC12_CDP,
+					port,
+					&charge);
+		charge_manager_update_charge(
+					CHARGE_SUPPLIER_BC12_DCP,
+					port,
+					&charge);
+		charge_manager_update_charge(
+					CHARGE_SUPPLIER_BC12_SDP,
+					port,
+					&charge);
+		charge_manager_update_charge(
+					CHARGE_SUPPLIER_OTHER,
+					port,
+					&charge);
+	}
+
+	/* notify host of power info change */
+	pd_send_host_event(PD_EVENT_POWER_CHANGE);
+}
+
+void usb_charger_task(void)
+{
+	const int attach_mask = PI3USB9281_INT_ATTACH | PI3USB9281_INT_DETACH;
+	int port = (task_get_current() == TASK_ID_USB_CHG_P0 ? 0 : 1);
+	int interrupt;
+	uint32_t evt;
+
+	/* Initialize chip and enable interrupts */
+	pi3usb9281_init(port);
+
+	bc12_detect(port);
+
+	while (1) {
+		/* Wait for interrupt */
+		evt = task_wait_event(-1);
+
+		/* Interrupt from the Pericom chip, determine charger type */
+		if (evt & USB_CHG_EVENT_BC12) {
+			/* Read interrupt register to clear on chip */
+			pi3usb9281_get_interrupts(port);
+			bc12_detect(port);
+		} else if (evt & USB_CHG_EVENT_INTR) {
+			/* Check the interrupt register, and clear on chip */
+			interrupt = pi3usb9281_get_interrupts(port);
+			if (interrupt & attach_mask)
+				bc12_detect(port);
+		}
+
+		/*
+		 * Re-enable interrupts on pericom charger detector since the
+		 * chip may periodically reset itself, and come back up with
+		 * registers in default state. TODO(crosbug.com/p/33823): Fix
+		 * these unwanted resets.
+		 */
+		if (evt & USB_CHG_EVENT_VBUS) {
+			pi3usb9281_enable_interrupts(port);
+#ifndef CONFIG_USB_PD_TCPM_VBUS
+			CPRINTS("VBUS p%d %d", port,
+				pd_snk_is_vbus_provided(port));
+#endif
+		}
+	}
+}
diff --git a/include/config.h b/include/config.h
index 73c42f08d5..709ee2e41e 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1947,7 +1947,7 @@
 /* Support USB blob handler. */
 #undef CONFIG_USB_BLOB
 
-/* Common USB / BC1.2 charger task */
+/* Common USB / BC1.2 charger detection routines */
 #undef CONFIG_USB_CHARGER
 
 /* Enable USB serial console module. */